Balancing machine attachment



Dec. 7,1943.

E. l. WENGER 2,336,429

BALANCING MACHIN E ATTACHMENT Filed May 12, 1941 W 25 24 7 INVENTOR niga'r ATTORNEY Patented Dec. 7, 1943 UNITED STATES PATENT OFFICE BALANCINGMACHINE ATTACHMENT Edgar I. Wenger, Philadelphia, Pa.

Application May 12, 1941, Serial No. 393,025

2 Claims.

My invention relates to balancing machines and attachmentsandparticularly to devices used to locate and measure the amount ofunbalance which can be mounted on the shaft or mandrel of the object tobe balanced.

An object of my invention is to decrease the time necessary to balancean object by providing an attachment for balancing machines which haveno so-called balancing head, the said attachment to be mounted on theshaft of the object to be balanced. This attachment is so arranged thatan artificial unbalance of varying amount and at various angulardisplacements can be maintained, controlled-and adjusted while theobject to be balanced is rotating. Thus by proper manipulation, theamount and angular location of the artificial unbalance may be made toexactly counter-balance the original unbalanced mass.

Another object of my invention is to provide an improved balancingmechanism of the type employing a movable element which is adjustableduring the rotation of the object to be balanced in order to determinethe location and/or amount of unbalance in said object while it isrotating.

In the accompanying illustrations Fig. 1 shows a side view of theattachment with certain parts shown broken away to reveal details. Fig.2 shows a plan view of the attachment with portions thereof broken awayto form substantially a longitudinal section of the attachment. Fig. 3is a schematic layout of a conventional balancing machine supportingstructure with the balancing attachment mounted on the shaft of theobject to be balanced. Fig. 4 shows the schematic diagram of theelectric wiring and control equipment.

In Figs. 1, 2 and 3 the clamp or attachment I is shown as mounted on theshaft 2 of the object to be balanced. A draw-in collett 3 is provided bymeans of which the attachment is clamped tightly to the shaft 2 thuscausing the entire attachment to revolve with it. Collett 3 carries asleeve 4 forming a journal or pivotal support for the non-magnetic block5 which carries two permanent magnets 6 and 6 on which are nonmagneticend pieces 1 and 8. End piece 7 is provided with a recess 9 which formsa bearing for the end of screw 10, the other end of which is held inblock 5. Screw l0 carries a motor armature II on which is mountedcommutator l2. Brush-holder l3 carries brushes which bear on commutatorl2. Contact pieces l6 and I1 connected to said brushes are arranged toslide along contact bars 20 and 2| which are secured to magnet 6 butinsulated therefrom by insulating strip I9. Conductors 22 and 23 bringelectric current from slip-rings 24 and 25 to which leads 26 and 21supply electric current through brush 23 carried on stationary supportor yoke 30. Thus armature H constitutes a movable mass, which movesradially toward or away from the center line of shaft 2, the directiondepending on the direction of flow of the electric current.

At the other end of the attachment and adjacent to end-piece 8 is amotor armature 32 mounted on shaft 34 which is carried in bearing 35 inend piece 8 and in bearing plate 35. Shaft 34 is mechanically coupled toa flexible shaft 31 which in turn is mechanically coupled to worm 38engaging a worm gear on or secured to the sleeve 4 as shown. On armature32 is mounted a commutator 33 on which bear brushes which receiveelectric current from leads 4| and 42 which are connected to slip rings43 and 44 on which bear brush 45 carried on stationary yoke 3%]. Brush45 is connected to conductors 4! and 48. Thus when electric current issupplied to the leads 4'! and 48 the armature 32 rotates in a directiondependent on the direction of flow of electric current, and the angularlocation of the balance indicating attachment with respect to shaft 2can be changed while the shaft is rotating.

Figure 3 shows a diagrammatic sketch of a balancing machine withpedestals 49 and 50 flexibly mounted on springs 5| and 52 on base 55,the amount of vibration of the pedestals 49 and 50 being partiallycontrolled by the adjustment of springs 53 and 54. Both pedestals 49 and50 are arranged so as to be free to vibrate or to be clamped in a fixedposition as desired. The removable bar H is arranged so that when bar (Iis in the position as shown both pedestals vibrate in unison. When bar His removed either of the pedestals 49 and 50 is free to vibrate orclamped in a fixed position as desired. The arm of pedestal 50 operatesa dial micrometer or indicator 58 by means of the arm 59 with fulcrumsupport shown at 60 while BI is an adjustable electrical contact deviceclosed by oscillation of the arm 59.

Figure 4 shows the schematic electrical diagram in which armature II isshown supplied with electric current from collector rings 24 and 25which in turn get their current through brushes from conductors 26 and21 leading from the reversing switch 64 which is connected to battery 10by lead 69 and also to a manually operated switch contact 62 which whenclosed is connected by conductor 68 to battery Ill. By reversing switch64 the direction of current flowing through armature II is reversed andthe direction of rotation is reversed. Thus the direction of rotationand amount of rotation of armature II can be readily controlled whileattachment I revolves with shaft 2. Contact 6I makes momentary contactwith each vibration of the pedestal 50 to effect automatic operation ofthe balancing means for approximate compensation, and balancingadjustment also may be made whenever desired by momentarily closing themanually operated contact 62. Similarly armature 32 gets its electriccurrent from conductors which are connected to collector rings 43 and44, on which bear brushes which are connected by conductors 41 and 48 tothe reversing switch 65. Switch 65 is connected, to switch blade 61which is manually operated and makes contact with conductor 68 and thusto battery 10. The other pole of the switch 65 is connected to theconductor 69 and thus to the other pole of bat-.- tery 70.

The operation of the balancing attachment is as follows: The object tobe balanced is placed on the balancing machine with the attachment Ifirmly secured to the shaft 2. The armature II is moved a short distancefrom its neutral or balanced position. The machine is then started, thebelt 56 causing the object to be balanced to rotate. The bar H being inplace, the two pedestals 49 and vibrate in unison and the indicator 58shows the amount of vibration or swing. The switch 61 is now closed withthe reversing switch 65 in the top position. If the indicator readingincreases as the switch 6| is periodically closed by the vibration ofthe pedestal 50, switch 61 is opened and the reversing switch 65 thrownto the lower position and the switch 61 closed again. The indicatorreading should now decrease and switch 61 is kept closed until a minimumreading is reachced when switch 61 is opened. The location of theattachment I now shows the angular position of the unbalanced mass. Nowwith the reversing switch 64 closed in the top position switch 62 isclosed momentarily. If the indicator reading increases the reversingswitch 64 is thrown to the lower position and switch 62 closed again.The reading of the indicator should now show a decreasing amount untilthe zero point is reached when the switch 62 is opened. The distance thearmature II has moved from its neutral position multiplied by its weightin ounces gives the amount of unbalance of the original and the centerline of attachment I gives the angular location of the unbalance. Theabove is, of course, for the correction of static unbalance and the sameprocedure with bar II removed and pedestal 49 secured in a fixedposition will locate the dynamic unbalance taking into account thedistances from the center line of pedestal 56 to center line ofattachment I and also from pedestal to the vertical plane where thecorrection can be made.

What I claim is:

1. In a balancing machine, the combination of a supporting means forrotatively supporting an object to be balanced and a frame arranged torotate with said object, adjustable weights mount- .ed in the frame, oneof said weights comprising an electric motor having its rotor arrangedto move along a path at an angle to the axis of said object when themotor is energized, the other .of said weights comprising a secondelectric motor arranged to move the frame angularly about the axis ofsaid object when it is energized.

2. The combination of a balancing machine and an electrically operatedbalancing mechanism or attachment mounted on the shaft of the object tobe balanced, said mechanism including an electric motor comprising arotatable armature having its axis disposed radially of said shaft, saidarmature being so constructed and arranged as to be movable along itsaxis, and means for energizing the motor while the object is rotating tovary the position of said armature with respect to the shaft.

EDGAR I. WENGER.

